New questions raised on leaked nuke waste mixture

ALBUQUERQUE, N.M. — New questions are being raised about what was mixed with the waste that caused a radiation release from the government's underground nuclear waste dump in southeastern New Mexico.

The Albuquerque Journal reported Thursday (http://bit.ly/1nxaRA5 ) that Los Alamos National Laboratory approved using products that some experts say are widely known to cause a heat reaction when mixed with other contents in the drums that were shipped to the Waste Isolation Pilot Plant near Carlsbad.

New Mexico Environment Secretary Ryan Flynn said the leading theory continues to be that the leak was caused by a reaction between nitrate salts and the organic cat litter packed with the waste to absorb moisture. However, emails posted online by the New Mexico Environment Department show Los Alamos approved using other organic ingredients known to be incompatible with nitrate salts in the waste.

The emails show that Los Alamos approved the use of two products requested by contractor EnergySolutions to neutralize the pH balance of drums sent to the nuclear waste dump.

In one email asking for approval in August 2013 to use a new liquid, EnergySolutions industrial hygienist Zeke Wilmot noted "criticality safety issues are not my area of expertise," using a term referring to nuclear engineering that focuses on preventing an inadvertent nuclear chain reaction.

Wilmot said "it may be advisable to have LANL personnel weight in on these issues as well."

A subcontractor approved the change in September.

In statements, officials with Los Alamos and the Waste Isolation Pilot Plant said they continue to investigate all possible causes of the Feb. 14 radiation leak that contaminated 22 workers with low levels of radiation and has shuttered the federal government's only permanent nuclear waste repository indefinitely. EnergySolutions did not respond to the newspaper's interview request.

The state Environment Department requested the emails as part of its probe into how decisions were made on changes in contents of the drums.

Flynn said he spoke with U.S. Energy Secretary Ernest Moniz on Thursday afternoon and had another round of meetings planned Friday with U.S. Department of Energy officials.

He said investigators are getting closer to figuring out what happened, but sampling still needs to be done on the materials inside the breached container

"It's really important for DOE to understand exactly what happened so we can begin to figure out what went wrong and how we can prevent this from occurring in the future," he said. "We're trying to get beyond the finger-pointing and really just focus on the investigation into what happened."